Hydrocarbon vapor and air mixing device



Oct. 25, 1938.

Oct. 25, 1938.- v LA, T, BARNES 2,134,021

HYDROCARBON VAPOR AND AIR MIXING DEVICE Filled Marh 25, 1935 2Sheets-Sheet 2 1.. INVENTOR Patented Oct. 25, 1938 UNiTED STATESHYDnocAaBoNvAPoR AND AIR MIXING DEVICE Llewellyn T. Barnes, Hempstead,N. Y.

Application March 25, 1935, Serial No. 12,920

8 Claims.`

The principal object of the invention is to produce a fuel v,vapor andair mixing device for internal combustion engines whereby the air andliquid fuel particles comprising therfuel mixture are brought intodesired intimate contact after issuing from` a carburetor whereby bettercombustible mixture is obtainedv for consumption in the cylinders of theengine.

Another object is to control the flow of the mixture in such a mannerthat undesirable vortexes and eddy current are eliminated, therebyimproving the quality, maintaining the improved quality of the vapormixture in varying quantities as desired.

Other objects are to improve fuel economy; to reduce the accumulation ofunconsumed deposits from partial combustion; andto generally improvevaporization of the liquid fuel to createa totally combustible mixture,

This invention contemplates Ythe incorporation of a simple, eicient andeasily installed Venturi tube of special design in the low pressure zoneoi and in the intake manifold located between the carburetor throttlevalve and the intakevalves of an internal combustion engine.

A further object of the invention is to provide a Yspecially constructedthrottle valve operative in connection with the aforesaid Venturi tube,to further improve mixture stability and toautomatically maintain asubstantially constant velocity of the mixture in its passage`throughftheexit zone of said Venturi tube; and to provide means wherebythe desired exit velocity of the mixture Ais maintained substantiallythroughout the entire working and speed range of the engine; and toeliminate condensation of the mixture on and around the throttle valveand in the walls of the intake manifold.

Figure 1 is a vertical sectional View through a portion of a carbureterand intake pipe, with one formof the invention applied,

Fig. 2 is an enlarged vertical sectional view of a portion thereof, withmodied intake passage,

Figure 3 is a horizontal section therethrough,

Figure 4 is an enlarged view showing-the .valve and a fragment of theVenturi tube in side elevation,

Figure 5 is a vertical section view of a modication,

Figure 6 is a View similar to Figure 3'of the modiiication,

Figure '7 is a vertical sectional view of the Venturi tube with criticaldimensions applied,

and

,Figure 8 is a vertical sectional View of a frag- (c1. 4s-1so) ment oftheVenturi tube with throat sections bent to yclosed positions.

Figure 9 is a vertical sectional View of a modiiication, j

Figure 10 is a horizontal view throughy its Venturi tube,

Figure 11 is a diagrammatical View illustrating principles of Figures 2and 9, and Figure 12 is a horizontal cross section of the valve stem ofFigure 9.

In the drawings, reference numeral i designates a-portion of .aninternalcombustion engine, I

' an intake port thereof, and 2 a standard type of carbureter,including-among other usual parts, a main discharge nozzle 3, mainmetering restriction il, valve seat and orifice 5, valve '6,acceleratingpump 1, step up passage 8, idling gas discharge holes 9 andair bleed opening I0, substantially as set forth in- Patent 1,909,389.

The carbureter communicates with the intake port I-fby meansof an intakepipe I2 attached to said intake pipe by bolts I4 passing through flangesI5 of the latter and threading into flanges I6 of the former. Betweenthese ilanges are clamped a pair of gaskets I'I and between the latteris clamped a thin metal gasket I8 to the bore of which is permanentlyaflixed the base oi a Venturi tube 20. The conical approach 2| of theventuri forms an angle of substantially 60 with its base, and therounded approach 22 to the exit portion 23 is formed on a radius ofsubstantially .6 of the throat diameter. The length of the exit portion23 is not less than three fourths of the mean throat diameter. Theserelative dimensions go to make up the novel venturi for preventing thebuilding up of a flow restricting vortex in the inlet cone by preventingan excessive amount of spinning of the gas vapor at highvelocity, thus.increasing the flow capacity of the tube. An active vortex would retardvelocity andupset a constant discharge co-efficient.

z While the walls of lthe Venturi exit portion 23 are normallyparalleLprovision is made for bending the walls thereof inwardly oroutwardly, this being permitted by V-shaped slots 24 providingintermediate throat sections 23. Bending the exit portion sections 23inwardly, thereby closing the slots 24, tends to decrease the exit area,and bending the exit sections outwardly opens the slots 24 and decreasesthe vortex and increases the exit area.

The slots 24 provide openings to permit the gradual expansion of themixture stream and also provide means to sever the liquid particles tomake moreV homogenous the mixture, diffusing the fuel particles in thevapor mixture more readily.` The slots also form individual eddycurrents that are helpful to the stream at the discharge side, byflattening out the ever-present vortex which is never entirelyeliminated, and which vortex is at a right angle to said eddy currents.

Drill holes 254 in the venturi of the juncture of l the exit sections 23and the rounded throat or approach portion tend to prevent fracture ofthe sections during bending thereof, and also assure openings even whenthe slots 24 are entirely closed, thereby preventing an excessive amountof fuel liquid being pocketed in the well 26.V

The Venturi tube described may be employed alone, as illustrated inFigure 5,:in which case the usual throttle valve 28 is employed, and thefeed of the carbureter, the reference character 2 is adjusted bychanging-the main metering discharge nozzle'3 to a smaller output andotherwise reducing the liquidV fuelsupply according to the particulartype of carbureter; Thus economy in fuel consumption is obtainedVthrough the use of the particular Venturi choke tube 20 and throughreadjustment of the carbureter.

Further mixture economy with greater power, may be obtained byelimination of the conventional throttle valve 28, provision of athrottling valve 30 in cooperation with the venturi 20, and extension ofthe step up passage by means of a tube 8 from the previous low pressureside to the new position of low pressure formed by use of throttlingvalve 30, together with recalibration of the carbureter as aforesaidvand by also reducing the stroke of the accelerating pump I and size ofthe valve seat orifice 4.

In eliminating the conventional throttle valve, a lever 3| issubstituted therefor and a link 32 extending therefrom through theVenturi tube 20 through a drill hole 33. The link rod 32 is free toslide within the drill hole but is conned from detachment-from the valve30 by a head 34; The drill holes 33 extend parallel with the valve axisand are formed at theinner ends of. V-shaped slots 35 formed in theconical skirt of the valve 3U, thereby providing bendable valve sections30 which may be bent inwardly or outwardly to close or open theslots 35kas in the case of the Venturi tube. Y Opposite side edges of each valvesection 3U are similarly beveled as at 35 to produce mixture spinning.

The hub 36 of the valve is centrally bored, the bore expandingVenturi-like at its bottom and upper ends 31, 38 respectively, lugs 39being disposed at intervals in theVenturi-face 38 Vto engage the bottomface of the adjusting nut. 40 to prevent closing of the Venturi passagebetween the surface 38 andthe nut 40. A coil spring 4| encircles the nut40 and the hub of the valve, and is held by its upper end 4| passingthrough the nut and engaging a flute of the .stem 42- upon which the nutis threaded. The lower end of the spring bears against the valve 3D inthe crotch between its conical skirt and its hub. i

The nut 40 is adjustably threaded upon the upper end of a fluted stem 42which is cruciform in cross section and which is formed on its lower endwith radial spider arms 42, having their outer ends extended through andclinched into slots 43 provided for this modification in the base of theventuri 20. The spider arms 42 also have shoulders 44 conforming toandengaged with the coni` cal approach 2| of the venturi to assist inmaintaining the guide stemA 42' centralized. The step-up passageextension tube 8 is bent to pass longitudinally up one of the guide stemflutes from the high pressure to the low pressure side of the venturi.

Normally, the floating valve 3|) is held closed upon the Venturi tube 20by the spring 4|, but suction when the engine is running lifts the valveagainst the pressure of, the spring to a` height limited by the positionof the throttle link stop head 34. When closed, an idling mixture flowsthrough the flutes of stem 42 and through the bore of the valve 30, theflutes preventing spinning of the idling mixture, 'and the spider arms42likewise preventing spinning of the main vapor charge, therebyeliminating a vortex. When the valve Vis open, sufficient vapor passesthrough the flutes and valve bore to compensate for the area displacedby the valve mechanism.

The slots in the Venturi tube 20 function the same whether the valve isemployed or not, and the slots in the valve may be opened or closed to agreater or less extent by bending the sections 30; thereby varying theslots. The valve itself, being conical, spreads the fuel vapor quicklyafter it leaves the Venturi tube 20, and maintains al constant velocityand a continued spreading of the mixture over the complete working rangeof the engine, regardless of, throttle position of the valve. The fuelvapor jets finding their way through the slots 35 issue from theupper'side of thevalve in a spinning condition, due to the beveled edges35 of the slots. These slots` 35 maintain spinning of the vapor as itissues therefrom even. when almost completely closed.

YWhile the invention has been described and illustrated in connectionwith an up-draft carbureter, it will be understood that the sameconditions exist relatively with a downdraft carbureter.

In the modified form shown in Figure 9, instead of a straight parallelwalled intake passage, against which the fuel vapor is deflected by thevalve, one having an outward bulge I 2 is employed, the bulge beingsurrounded by a heating jacket I3 for exhaust, auxiliary heat or otherfluid. Interiorly, this bulged wall 'I2' is provided with spiral finsI2" which are notched to provide an operating guide for the valve 3|)athe latterbeing substantially the same structurally and functionally asthe valve 30 of the first form. This vvalve has a stem 36a cruciform incross sectionV and is formed with a longitudinal slot 36 which has alateral branch slot 36 in which latter a crank pin 3| on a crank 3|operates, the crank being attached to a shaft 3| substituted for theconventional throttle valve shaft.

In assembling, when the heater section. and carbureter sections aremoved together, the'pin 3| enters the slot'36 and then the branch'slot36" and thereafter the shaft 3|X enters the slot 36 and reposes at theend thereof. An operating arm 3|EL is provided for the shaft 3|x and isnormally urged downwardly by a tension spring 4|n to normally urge thevalve toward closed position. Anyvform of external spring means may besubstituted for this purpose. The shoulders I2n prevent the valvelifting to a point where crank pin 3| will leave the branch slot 36".

In this modification, the Venturi tube 20, like the bulged wall I2', isan insert within the heater section of the intake section and isprovided with vortex preventing'grooves 2|)b as well as a stepup fuelfeeding passage 8l. The ribs and grooves of the cruciform valve stem 36aassist grooves .201? in preventing spinning of. the vapor.V This step-uppassage is provided to supply additional liquid fuel under certainconditions such as emergency high loads. Under certain other conditionswith certain carbureters, this additional fuel may be forced through thestep-up passage by the operator; and in connection with certain othercarbureters, the additional fuel is automatically passed through thispassage in response to the predetermined demand. The outlet of thestep-up passage is in the valve seat of the valve 302,A f

`While the advantages of a properly proportioned Venturi tube arepresent inV all forms of the invention, an added advantage is present inthe bulging of the intake passages or portrayed in the diagram, theobject of a properly proportioned bulged intake passage and dischargethroat is to maintain a desired constant velocity at all engine speeds.By making the throat discharge passage with a cross-sectional area of X,the valve or spreader with a cross-sectional area of. X/2, and with across-sectional area of X/Z between the valve stem and Venturi throat, across-sectional area of X/2 must be maintained for the annulus betweenthe valve and the bulged intake passage wall for top engine speed whenthe valve is fully open.

When the spreader valve is approximately half closed, because of lowerengine speed, a velocity substantially equal to the velocity at higherspeeds should be maintained and this is accomplished by curving thepassage wall inwardly at that point to give cross-sectional area of X/4between the half-open valve and the passage wall, the cross-sectionalarea of the annulus between the bulged wall and the tapered Side of thevalve being reduced also to X/4. The crosssectional area of the Venturithroat has a constant of X/2.

What is claimed:

l. In a mixing device of the character described, a pipe line leadingfrom a source of vapor supply to the intake of an internal combustionengine, a Venturi tube in said pipe line, a iiuted stem passing axiallythrough the Venturi tube, and a valve adapted for cooperation with theexit portion of said Venturi tube and having a bore through which thestem passes, a nut threaded upon the stem, and a spring having one endbearing against the valve and its other end passing` through the nutinto engagement with the flutes of the stem.

2. In a mixing device of the character described having a pipe lineleading from a source of vapor supply to the intake of an internalcombustion engine, the combination of a Venturi tube member located inthe pipe line, said Venturi tube having a conical mouth portion, arounded throat portion, and a substantial cylindrical discharge portion;a conical valve member having its tip end located within the dischargeportion of the Venturi tube and its sides adjacent its base engaged withthe end of the discharge portion of the Venturi tube when said valve isin its closed position, and guide means to coniine the movement of saidvalve in a direction axially of said Venturi tube in its opening andclosing movements, one of said members being provided with vortexdisturbing slots extending in the general longitudinal direction of theaxis of the Venturi tube.

3. In a mixing device of the character described having a pipe lineleading from a source of vapor supply to an intake of an internalcombustion engine, the combination of a Venturi tube located in the pipeline, said Venturi tube having a coni'- cal mouth portion, a roundedthroat portion, and

a substantially cylindrical slotted discharge portion; a conicalthrottle valve mounted to move .axially of the Venturi tube and When inclosed position having its tip end located within the Venturi tube andits sides adjacent its base seated upon theV end of the dischargeportion of the Venturi tube, means working through said Venturi tube foroperating the valve, and a tube from the source of vapor supplycommunicating through said valve with the low pressure side of theVenturi tube.

4. In a mixing device of the character described having a pipe lineleading from a source of vapor supply to the intake of an internalcombustion engine, the combination of a Venturi tube located in the pipeline, said Venturi tube having a conical mouth portion, a rounded throatportion, and a slotted substantially cylindrical dischargeV portion; aconical throttle valve mounted to move axially of the Venturi tube intoand out of closing engagement with the end of the discharge portion ofsaid Venturi tube, the tip end of the valve being located within theVenturi tube and the sides of the valve adjacent its base seating uponsaid discharge end of the Venturi tube when the valve is closed, theValve having an axial bore, a iiuted valve guide arranged within saidbore axially of the Venturi tube, and a tube leading from the source ofvapor supply and located in one of the ilutes of the valve guide and inthe bore of the valve to discharge vapor into the latter.

5. In a mixing device of the character described having a pipe lineleading from a source of vapor supply to the intake of an internalcombustion engine, the combination of a Venturi tube member located inthe pipe line, said Venturi tube having a conical mouth portion, arounded throat portion, and a substantial cylindrical discharge portion;a conical valve member having its tip end located within the dischargeportion of the Venturi tube and its sides adjacent its base engaged withthe end of the discharge portion o1' the Venturi tube when said valve isin its closed position, and guide means to confine the movement ofsaidvvalve in a direction axially of said Venturi tube in its openingand closing movements, said discharge portion being provided withvortexv disturbing slots extending in the general loigitudinal directionof the axis of the Venturi tu e.

6. In a mixing device of the character described having a pipe lineleading from a source of vapor vsupply to the intake of an internalcombustion engine, the combination of a Venturi tube member located inthe pipe line, said Venturi tube having a conical mouth portion, arounded throat portion, and a substantial cylindrical discharge portion;a conical valve member having its tip end located within the dischargeportion of the Venturi tube and its sides adjacent its base engaged withthe end of the discharge portion 0I ply to the intake `of aninternalcombustion 'ensaid Venturi tube havingk a converging entranceportion leading to a throat and having a substantially cylindricaldischarge lportion beyond the throat portion, said discharge .portionbeing spaced from said pipe lineandy provided. with longitudinal vortexdisturbingY slots through which minorpportions of the vapor'in passingthrough said slotsis directed substantially'coni-l cally, said slotsproviding `substantially cylindrically arcuate segments comprising saiddischarge portion,k whereby the major portion of said vapor issubstantially conned inan unswirled column and flowing in a directioncoextensive with said discharge portion substantially throughout saidpipe line portion. .i Y

8. A mixing device of the character described including in combination aunidirectional portion of a pipe line leading from a source of vaporsupply to an intake of a combustion enginesaid portion including anenlargedconcentric annular portion, said annular portion providing aconcave annular passage, a Venturi tube in said portion and disposedcoaxially and concentrically therein, said Venturi tube having a conicalmouth portion, an arcuate throat portion, and a substantiallycylindrical discharge portion terminating substantially upstream ofVsaid enlarged annular portion and spaced from said pipe line, a conicalthrottle valve having its tip end located Within the discharge passageof the Venturi tube, said valve having its sides adjacent its baseengageable with the end of theV discharge portion of the Venturi tubewhen said valve is in its closed position, and guide means to direct themovement of said valve axially of said Venturi tube whereby the vaporpassing said Valve is deflected .into said concave passageway during allopen positions of said valve.

LLEWELLYN T. BARNES.

